如何拆分Django项目为应用？GitHub类层级项目拆分及目录疑问

Great question! When breaking down a GitHub-like platform into Django apps, the key is to follow Django's philosophy of loose coupling and high cohesion—each app should handle a single, focused domain or feature set that can (theoretically) be reused elsewhere if needed. Let's break this down step by step.

Core Principles for Splitting Apps #

Before diving into specifics, keep these rules in mind:

• Single Responsibility: Each app should own one clear business domain. Don't mix user authentication with issue tracking, for example.
• Independence: Minimize direct dependencies between apps. Use foreign keys, Django signals, or abstract interfaces to connect them instead of hardcoding calls between app modules.
• Reusability: If a feature could be pulled out and used in another project (like user accounts), it's a good candidate for a standalone app.

Breaking Down a GitHub-like Platform #

Let's map GitHub's core features to Django apps and identify what doesn't belong in an app:

Apps You Should Create #

• accounts: Handles everything user-related—extending Django's default User model, login/signup, profile management, email verification, and permission basics (like who can access a repo). This is a foundational app that most other features will depend on, but it stays focused on identity and access.
• repositories: Manages repo core logic—creating/deleting/editing repos, setting repo-level permissions, and storing repo metadata (descriptions, branch info, visibility settings). Note: You don't need a separate app for Git operations (like pulling/pushing code); that can live in a services submodule within this app or a global utility folder.
• issues: Owns the full lifecycle of issues—creating tickets, adding comments, assigning labels/statuses, and linking to pull requests. Even though issues are tied to repos, they're a distinct business domain worth isolating.
• pull_requests: Handles PR-specific logic—creating PRs, code review workflows, merging/declining PRs, and syncing with linked issues. PRs have unique workflows that don't fit neatly into issues or repos, so a standalone app makes sense.
• notifications: Manages cross-platform alerts—repo update reminders, issue/PR comment notifications, and @mention alerts. This app can listen for signals from other apps (e.g., when an issue is created) to trigger notifications without tight coupling.
• organizations (if needed): Manages team/organization entities—creating orgs, adding/removing members, and setting org-wide repo permissions. It ties into accounts but focuses on group identity rather than individual users.

What Doesn't Belong in a Django App #

• Core Project Configuration: Files like settings.py, the root urls.py, global middleware, and WSGI/ASGI configs are part of your project's foundation, not a business app.
• Global Templates & Static Assets: Base templates (navbars, footers) and shared CSS/JS should live in root-level templates and static folders. Reserve app-specific templates/static for features unique to that app (e.g., issue comment forms).
• Low-Level Service Logic: Tools like Git integration, file storage, or API client wrappers are utility functions, not standalone apps. Place these in a root utils or services folder, or as submodules within the app that uses them (e.g., repositories/services/git_service.py).
• Cross-App Workflows: Logic like "auto-close an issue when its linked PR is merged" shouldn't be an app. Instead, use Django signals (listen for PR merge events in the pull_requests app, then update the issue in the issues app) or a dedicated workflows module.

Where to Place Your Apps #

Django's default convention is to place apps at the project root, alongside your main config directory:

github_clone/
├── github_clone/       # Main project config
│   ├── settings.py
│   ├── urls.py
│   └── asgi.py
├── accounts/
├── repositories/
├── issues/
├── pull_requests/
└── manage.py

If you have a large number of apps (5+), you can group them in a dedicated apps/ folder for better organization. Just make sure to add this folder to your Python path (via sys.path in settings.py) or reference apps by their full path in INSTALLED_APPS:

github_clone/
├── github_clone/
├── apps/
│   ├── accounts/
│   ├── repositories/
│   └── ...
└── manage.py

Either way, every app should be a valid Python package (with an __init__.py file and core modules like models.py, views.py).

A Quick Note on Granularity #

Don't over-split! For example, don't make a separate issue_comments app—comments are a core part of issues, so they should live in a comments submodule within the issues app. Find a balance between avoiding monolithic apps and not creating too many tiny, hard-to-manage apps.

内容的提问来源于stack exchange，提问作者user9486747